[!FROZEN] MPLP Protocol v1.0.0 Frozen Specification Freeze Date: 2025-12-03 Status: FROZEN (no breaking changes permitted) Governance: MPLP Protocol Governance Committee (MPGC) License: Apache-2.0 Note: Any normative change requires a new protocol version.

Event Taxonomy

1. Purpose

The Event Taxonomy defines the classification system for all MPLP observability events. It organizes 12 Event Families into semantic groups and maps them to physical schemas.

2. Event Family Classification

2.1 Complete Family List

ID	Title	Compliance	Schema
graph_update	GraphUpdateEvent	REQUIRED	mplp-graph-update-event.schema.json
pipeline_stage	PipelineStageEvent	REQUIRED	mplp-pipeline-stage-event.schema.json
runtime_execution	RuntimeExecutionEvent	RECOMMENDED	mplp-runtime-execution-event.schema.json
import_process	ImportProcessEvent	RECOMMENDED	mplp-event-core.schema.json
intent	IntentEvent	RECOMMENDED	mplp-event-core.schema.json
cost_budget	CostAndBudgetEvent	RECOMMENDED	mplp-event-core.schema.json
external_integration	ExternalIntegrationEvent	RECOMMENDED	mplp-event-core.schema.json
delta_intent	DeltaIntentEvent	Optional	mplp-event-core.schema.json
impact_analysis	ImpactAnalysisEvent	Optional	mplp-event-core.schema.json
compensation_plan	CompensationPlanEvent	Optional	mplp-event-core.schema.json
methodology	MethodologyEvent	Optional	mplp-event-core.schema.json
reasoning_graph	ReasoningGraphEvent	Optional	mplp-event-core.schema.json

2.2 Family Groups

3. Group A: Intent & Planning

3.1 intent

Purpose: Capture user's raw requests and intentions

Field	Type	Description
intent_id	UUID	Intent identifier
source	Enum	Input source (ui, api, cli)
raw_text	String	Original user input
parsed_intent	Object	Structured intent

Example:

{
  "event_type": "intent_received",
  "event_family": "intent",
  "payload": {
    "intent_id": "int-001",
    "source": "ui",
    "raw_text": "Fix the login bug in auth.ts",
    "parsed_intent": {
      "action": "fix",
      "target": "auth.ts",
      "issue": "login bug"
    }
  }
}

3.2 delta_intent

Purpose: Track modifications to existing intents

Field	Type	Description
original_intent_id	UUID	Original intent reference
delta_type	Enum	add, modify, remove
changes	Object	Specific changes

3.3 methodology

Purpose: Track agent's approach selection

Field	Type	Description
method_id	String	Methodology identifier
name	String	Method name
rationale	String	Why this approach

3.4 reasoning_graph

Purpose: Capture chain-of-thought reasoning

Field	Type	Description
thought_chain	Array	Reasoning steps
conclusion	String	Final decision
confidence	Number	Confidence score

4. Group B: Execution & Lifecycle

4.1 pipeline_stage (REQUIRED)

Purpose: Track Plan/Step lifecycle transitions

Field	Type	Description
stage_id	UUID	Stage identifier
resource_type	Enum	plan, step, context
resource_id	UUID	Resource reference
from_status	String	Previous status
to_status	String	New status

Trigger Points:

• Plan: draft proposed approved in_progress completed
• Step: pending running completed/failed

Example:

{
  "event_type": "pipeline_stage_transition",
  "event_family": "pipeline_stage",
  "payload": {
    "stage_id": "stage-001",
    "resource_type": "plan",
    "resource_id": "plan-550e8400",
    "from_status": "proposed",
    "to_status": "approved",
    "reason": "User approval via Confirm"
  }
}

4.2 runtime_execution (RECOMMENDED)

Purpose: Track low-level execution details

Field	Type	Description
execution_id	UUID	Execution identifier
executor_type	Enum	llm, tool, agent
operation	String	Operation name
duration_ms	Number	Execution time
status	Enum	success, failure, timeout

Example:

{
  "event_type": "llm_call_completed",
  "event_family": "runtime_execution",
  "payload": {
    "execution_id": "exec-001",
    "executor_type": "llm",
    "operation": "generate_code",
    "model": "gpt-4",
    "duration_ms": 2500,
    "tokens_in": 500,
    "tokens_out": 200,
    "status": "success"
  }
}

4.3 external_integration

Purpose: Track external system interactions

Field	Type	Description
integration_id	String	Integration identifier
system	String	External system name
operation	String	Operation performed
response_status	Number	HTTP status or code

4.4 cost_budget

Purpose: Track token usage and financial metrics

Field	Type	Description
tokens_used	Number	Tokens consumed
cost_usd	Number	Estimated cost
budget_remaining	Number	Remaining budget
model	String	Model identifier

Example:

{
  "event_type": "token_usage_recorded",
  "event_family": "cost_budget",
  "payload": {
    "plan_id": "plan-001",
    "model": "gpt-4",
    "tokens_used": 1500,
    "cost_usd": 0.045,
    "budget_remaining": 49.955,
    "cumulative_tokens": 15000
  }
}

5. Group C: State & Safety

5.1 graph_update (REQUIRED)

Purpose: Track PSG structural changes

Field	Type	Description
update_id	UUID	Update identifier
operation	Enum	create, update, delete
node_type	String	Node type affected
node_id	UUID	Node identifier
previous_state	Object	State before change
new_state	Object	State after change

Trigger Points:

• Node created/updated/deleted
• Edge added/removed
• Attribute modified

Example:

{
  "event_type": "node_created",
  "event_family": "graph_update",
  "payload": {
    "update_id": "upd-001",
    "operation": "create",
    "node_type": "plan_step",
    "node_id": "step-550e8400",
    "new_state": {
      "step_id": "step-550e8400",
      "description": "Read error logs",
      "status": "pending"
    }
  }
}

5.2 impact_analysis

Purpose: Track predicted side-effects

Field	Type	Description
impact_id	UUID	Analysis identifier
affected_resources	Array	Resources impacted
risk_level	Enum	low, medium, high, critical
recommendations	Array	Suggested actions

5.3 compensation_plan

Purpose: Track rollback planning

Field	Type	Description
compensation_id	UUID	Plan identifier
reason	String	Why compensation needed
steps	Array	Rollback steps

5.4 import_process

Purpose: Track project initialization

Field	Type	Description
import_id	UUID	Import identifier
source_type	Enum	git, local, zip
files_scanned	Number	Files processed
cards_generated	Number	Semantic cards created

6. Schema Mapping

7. Related Documents

Observability:

• Observability Overview - Architecture
• Module Event Matrix - Module mapping
• Event Taxonomy YAML - Machine-readable

Schemas:

• schemas/v2/events/mplp-event-core.schema.json
• schemas/v2/events/mplp-graph-update-event.schema.json
• schemas/v2/events/mplp-pipeline-stage-event.schema.json
• schemas/v2/events/mplp-runtime-execution-event.schema.json

---

Document Status: Normative (Event Classification)
Total Families: 12
Required: pipeline_stage, graph_update
Recommended: runtime_execution, import_process, intent, cost_budget, external_integration
Optional: delta_intent, impact_analysis, compensation_plan, methodology, reasoning_graph

2025 Bangshi Beijing Network Technology Limited Company Licensed under the Apache License, Version 2.0.